There are known techniques of recognizing an operation of a user from an image captured by an image capturing device, and performing control or processing according to the recognized operation. As an input interface in a case where a user uses a display device mounted on the head of the user and disposed in front of an eye of the user, some of the aforementioned techniques are known to recognize various operations of the user from images of gestures performed by the user as the operations and captured by an image capturing device.
Meanwhile, there are also known techniques of determining whether an operation of a user is a failure, and determining whether recognition of an operation of a user is a failure. There is also known a technique of presenting a correct operation when the operation of a user is determined to be a failure.
Related techniques are disclosed, for example, in Japanese Laid-open Patent Publication Nos. 2011-215856, 2011-209787, 2001-216069, and 2000-259307.